This invention relates generally to cable-controlled brakes for vehicles, and more particularly to a device which reduces the tendency of a wheel to lock in response to the application of a braking force.
Conventionally, bicycles are provided with right and left hand braking levers which operate the rear and front brakes, respectively, by means of cables. Minimum stopping distance is achieved when both such levers are operated simultaneously. The actuation of either lever independently of the other when it is necessary to stop quickly, may expose the operator to a less than acceptable stopping condition. In bicycles of the type having downward sweeping handlebars to reduce operator wind resistance, the operator is positioned on the bicycle so as to lean forward, thereby distributing a majority of the weight over the front wheel. Under these conditions and others described herein the rear wheel has very little stopping capability and could easily lock causing the bicycle to skid. Thus, the application of only the rear-wheel brake in an emergency situation may probably not bring the bicycle to a stop within a suitable distance.
Further, the application of only the front-wheel brake in an attempt to stop a bicycle in an emergency situation can produce a braking force which can cause the front wheel to reach a lockup threshold, sooner than under normal conditions. This could cause the bicycle to pivot forward about the hub of the front wheel.
One attempt to overcome the problems noted above is described in U.S. Pat. No. 4,057,127. This reference describes an apparatus which can permit the actuation of both front and rear brakes in tandem by operation of only one control lever. Moreover, actuation of the front brake is applied subsequent to the rear brake, the duration of delay being determined by an amount of time necessary to compress a spring, or to upset a lever arm.
It is, therefore, an object of this invention to improve bicycle braking systems so as to permit rapid deceleration and stopping, while reducing the potential tendency of bicycle to pivot about the front wheel hub and perhaps force the operator over the handlebars.
It is a further object of this invention to improve the tactile feedback available in operating the bicycle brake actuation levers.
It is another object of this invention to provide a bicycle braking system which controls the application of a braking force to a wheel without increasing the time period between the actuation of the brake lever and the application of the braking force at the wheel.